tried it with the three examples above many times with different icons, but still none of them gets overwritten...Nx titles dumper should show you the tid of all installed titles, refer to the CSV list it will be in there.
title IDs > Show List of Installed Games (CSV)
As for icons not working I'm 99% sure all the icons work but if it's a grey questionmark I will gladly fix it.
If you are stuck there might be an answer for you here; https://sodasoba1.github.io/NSW-Custom-Game-Icons/